PC USB主机通过libusb与Android附件模式通信

Question

I want to communicate to Android accessory mode from HOST PC(linux) through libusb and I have already set up android accessory mode. but I can't get usb handle.

$ lsusb
Bus 001 Device 010: ID 18d1:2d00 Google Inc. Android-powered device in accessory mode

when I use libusb to get this usb handle , it always return NULL. How to fix it ? Thanks.

libusb_init(NULL);
struct libusb_device_handle* handle = libusb_open_device_with_vid_pid(NULL, 0x18d1,0x2d00);
// this handle always return NULL

Answer 1

I opened debug message in libusb by libusb_set_debug(NULL, 3); And I found that this user do not have permission to visit this usb device.

I fixed it by adding a file named 51-android.rules in /etc/udev/rules.d/

51-android.rules :

SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", MODE="0666", GROUP="plugdev"